U.S. Pat. No. 5,132,708 discloses a direct printing apparatus. In the direct printing apparatus, four printing stations are disposed on an outer periphery of a drum-like sheet conveying member along a sheet conveying direction. On an outer periphery of a toner carrier in each printing station is retained toner having different colors, for example, magenta, cyan, yellow and black.
Moreover, in the direct printing apparatus, a plurality of aspirators comprising a vacuum cleaner and the like are provided inside the sheet conveying member. Each aspirator sucks the sheet to hold it on the outer periphery of the sheet conveying member and sucks the toner adhering to each printing station to clean the printing station at a cleaning time after printing operation.
However, the direct printing apparatus as described above utilizes the aspirator comprising the vacuum cleaner, thereby there is a disadvantage that a noise is caused when operating the aspirator. The aspirator is provided inside the sheet conveying member, thereby there is an another disadvantage that the apparatus is enlarged. In addition, since the sheet is sucked by the aspirator, it is necessary to form a number of holes in the sheet conveying member. Thereby, there is a further disadvantage that the strength of the sheet conveying member becomes weakened.